Burglar-alarm.



R. L CADENHEAD. BURGLAR ALARM.

APPLICATION FILED APR. 1?, 1917.

1 li,'?@'?. Pented Feb. 5,1918.

RENA LCADEIIHEAD, OF GEORGETOWN, GEORGIA.

BURGLAR-ALARM.

Application filed April 17, 1917.

To all whom it may concern:

Be it known that I, RENA L. OADENHEAD, a citizen of the United States, residing at Georgetown, in the county of Quitman and State of Georgia, have invented new and useful Improvements in Burglar-Alarms, of which the following is a specification.

This invention relates to burglar alarms, especially adapted for use on doors, windows and other closures and has for one of its objects, the provision of an extremely simple alarm wherein clock mechanism is employed to sound the alarm when tripped by the opening of a door or window.

Another object of the invention is to provide a burglar alarm having spring actuated mechanism to operate a bell hammer which mechanism is provided with a winding key or head having a notch formed therein into which is adapted to extend, when the door, window or other closure is shut, an arm to hold the key against rotation, said arm being tripped from engagement with the key when the closure is opened.

The invention also aims to generally. im prove devices of this nature to render them more practical, useful and commercially desirable.

With these and other objects in view as will become more apparent as the description proceeds, the invention consists in certain novel features of construction, combination and arrangement of parts as will be hereinafter fully described, illustrated and claimed.

' In the drawings,

Figure l is a perspective view showing the application of the alarm to a door.

Fig. 2 is a side elevation of the alarm mechanism, and

Fig. 3 is a front elevation.

Referring in detail to the drawings by numerals, 1 designates an automatic signal comprising a housing or casing 2 in which is mounted spring actuated clock mechanism 3 having a winding shaft 4 to which is attached a winding key or head 5 having a horizontal outwardly opening slot 6. The clock mechanism actuates a hammer 7 to sound the hell 8 and thus give the alarm. To hold the winding shaft against rotation when the alarm is not in use, I provide a latch 9 which is pivoted adjacent one end Specification of Letters Patent.

Patented Feb. 5, 1918.

Serial No. 162,694..

of the casing as at 10 and which swings in a plane at right angles to the shaft. This latch is notched as at 11 to engage the key 5 and hold the same against rotation. The mechanism may be secured, in close proximity to the door opening, when the alarm is used on doors, or may be secured to the window casing when used on windows.

The door 12, which I have illustrated for the purpose of showing the application of my alarm, is equipped with an arm 13 which, when the door is closed, lies within the notch in the key to prevent the key rotatmg.

To set the alarm the spring of the clock mechanism is wound by rotating the key 5 and then held under tension by the latch 9. The door is then closed to carry the arm 13 into the notch of the key, after which the latch 9 is drawn into inoperative position away from engagement with the key. Now when the door is opened, the arm 13 will be carried out of the notch in the key allowing the clock mechanism to sound the bell and give the alarm.

It will be noted that this device is extremely simple, very practical and capable of adaptation to various closures, such as doors, windows, transoms and the like.

While I have shown and described the preferred embodiments of my invention it will be clearly understood that I do not wish to be limited to this construction, but may make such changes as will fall within the scope and spirit of the invention, as claimed.

What I claim is 1. In a closure controlled burglar alarm, an automatic signal including a notched key rotatable when the signal is operating, and means carried by the closure to engage in said notch to hold the key against rotation when the closure is shut, said means becoming disengaged from the key when the closure is opened.

2. In a burglar alarm for closures, an automatic signal mounted adjacent said closure and including a notched key, said key being adapted when rotated in one direction to energize the signal and rotating in the other direction when the signal is operating, means for holding the key against rotation, an arm carried by the closure and adapted to be swung into said notch when the closure is shut, said arm moving from the slot When the closure is opened.

3. In a burglar 'alarm for closures, an automatic signal including a Winding key 5 having a horizontal' Outwardl opening notch, an arm carried by the c osure and adapted to be swung into said notch when the closureis shut, and means detachable from-the key-for holding the latter in position to receivethe arm when the 'signalr is'io beingset In testlmony whereef aflii; my signature RENA L. CADENHEAD,

Copies bfthis patent may be obtained for five cents each, by addres sing the cdnimis sionerot fa t ents, I i r Washington, D. G, u 

